1. Field of the Invention
This invention generally relates to a bicycle suspension system. More specifically, the present invention relates to a bicycle suspension system comprising a switching mechanism between air chambers.
2. Background Information
Bicycling is becoming an increasingly more popular form of recreation as well as a means of transportation. Moreover, bicycling has become a very popular competitive sport for both amateurs and professionals. Whether the bicycle is used for recreation, transportation or competition, the bicycle industry is constantly improving the various components of the bicycle. In the past, most bicycles had rigid frames and forks which typically transmitted the shocks resulting from rough riding surfaces directly to the rider. In other words, most bicycles were not provided with any front or rear suspension. Recently, bicycles, especially mountain bikes (MTB) and all terrain bikes (ATB), were introduced that included front suspension forks to absorb the shocks transmitted to the rider when riding on a rough road. This made riding on rough terrain easier and less physically stressful.
The first suspension forks had about 1½ to 2 inches (38 to 50 mm) of suspension travel. Forks are now available with about 4 to 6 inches (100 to 150 mm) of suspension travel or more. Bicycles with front suspension and rigid, non-suspended rear wheels, or hardtails became popular nearly overnight. On most mountain bicycles, the front fork contains a set of shock absorbers. The suspension travel and handling characteristics vary depending on the type of mountain biking the fork is designed for. For instance, bicycle manufacturers produce different forks for cross-country (XC), downhill and freeride riding.
The shock absorber usually includes a spring and a damper or dashpot. The spring may be implemented with a steel or titanium coil, an elastomer, or even compressed air. The damper is usually implemented by forcing oil to pass through one or more small openings or shim stacks. On some bicycles, the spring, the damper, or both may be adjusted for rider weight, riding style, terrain, or any combination of these or other factors. Also, the two components are sometimes separated with the spring mechanism being in one leg and the damper being in the other leg.
In these bicycles with front suspension forks, it is sometimes desirable to be able to quickly adjust the suspension stroke and/or the spring rate of the spring mechanism as needed and/or desired. Thus, there have been proposals to provide suspensions that include adjust the suspension stroke and/or the spring rate of the spring mechanism.